# 开发时间: 2023/9/5 16:43
score=int(input("请输入你的分数"))
#判断
if score>=90 and score<=100:  #还可以这样写，90<=score<=100
    print("A级")
elif score>=80 and score<=89:
    print("B级")
elif score>=70 and score<=79:
    print("C级")
elif score>=60 and score<=69:
    print("D级")
elif score>=0 and score<=59:
    print("不及格")
else:
    print("请输入正确的分数")
